This invention relates to charge valves for air conditioning systems, and in particular to charge valves that provide extremely low leakage rates.
Air conditioner systems typically include a charge valve positioned on an air conditioner line of the system. A refrigerant fluid is introduced into the system via the charge valve. In the past, charge valves have typically included a valve core that is threaded in place in a valve body. The valve core is depressed or removed for charging operations, and once installed the valve core relies on an elastomeric seal to close the charging passageway. See for example the arrangement disclosed in White U.S. Pat. No. 3,299,648.
U.S. patent application Ser. No. 09/472,260, assigned to the assignee of the present invention, discloses another charge valve that uses a twist-to-open valve that forms a metal to metal seal when closed. This twist-to-open valve is threadedly engaged with the valve body, and rotation of the valve moves it axially with respect to the valve body.
A need presently exists for an improved charge valve that is low in cost, that is simple to operate, and that provides a leak-free seal when closed.
By way of introduction, the charge valves described below include a valve body that defines a bore that is in fluid communication with an air conditioner line via a valve seat. A slide-to-seal valve element is positioned in the bore in an interference fit with the valve body. This valve element is shaped to open the valve at the valve seat when in an opened position and to seal the valve at the valve seat when in a closed position. The interference fit retains the valve element in the closed position without any threaded connection between the valve element and the valve body. A charging passage having an inlet on one side of the valve element and an outlet on the other side of the valve element is positioned to conduct charging fluid across the valve element and through the valve seat when the valve element is in the opened position. Once the air conditioning system has been charged, the valve element is rammed to the closed position, without any substantial rotation, and the interference fit described above maintains the valve element in the closed position.
This section has been provided by way of general introduction, and it is not intended to narrow the scope of the following claims.